Disclosures About Segments And Related Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Segment Reporting Information [Line Items]
Earnings after income tax	$ 4,940		$ 9,100
Sales and other operating revenue	64,758	[1],[2]	101,312	[1],[2]
Upstream United States [Member]
Segment Reporting Information [Line Items]
Earnings after income tax	(52)		1,244
Sales and other operating revenue	2,125	[1]	3,874	[1]
Intersegment Revenue	1,180		2,063
Upstream Non-U.S. [Member]
Segment Reporting Information [Line Items]
Earnings after income tax	2,907		6,539
Sales and other operating revenue	4,122	[1]	5,827	[1]
Intersegment Revenue	4,857		10,781
Downstream United States [Member]
Segment Reporting Information [Line Items]
Earnings after income tax	567		623
Sales and other operating revenue	18,389	[1]	30,412	[1]
Intersegment Revenue	3,076		4,909
Downstream Non-U.S. [Member]
Segment Reporting Information [Line Items]
Earnings after income tax	1,100		190
Sales and other operating revenue	33,162	[1]	51,288	[1]
Intersegment Revenue	5,273		12,842
Chemical United States [Member]
Segment Reporting Information [Line Items]
Earnings after income tax	605		679
Sales and other operating revenue	2,792	[1]	3,876	[1]
Intersegment Revenue	1,773		2,634
Chemical Non-U.S. [Member]
Segment Reporting Information [Line Items]
Earnings after income tax	377		368
Sales and other operating revenue	4,166	[1]	6,032	[1]
Intersegment Revenue	1,321		2,267
All Other [Member]
Segment Reporting Information [Line Items]
Earnings after income tax	(564)		(543)
Sales and other operating revenue	2	[1]	3	[1]
Intersegment Revenue	$ 68		$ 67

[1] Includes sales-based taxes

[2] Sales-based taxes included in sales and other operating revenue for the three months ended March 31, 2015, and 2014, were $5,530 million and $7,416 million, respectively.